Regulatory Controls and Enforcement
The City of Minneapolis enforces ordinances designed to minimize stormwater runoff pollution. Minneapolis ordinances authorize these efforts:
- Requiring erosion and sediment control for new developments and residential housing to reduce the amount of sand and dirt leaving construction sites
- Requiring long term stormwater management for new developments to eliminate post development increases in pollution and runoff volumes
- Controlling the application of pesticides by licensing applicators and restricting the sale and use of fertilizers containing phosphorus
- Controlling hazardous spills and enforcing regulations that prohibit illegal dumping and improper disposal into the storm drain system
- Preventing violations of non-stormwater discharges (industrial by-products that are cleaned or treated prior to discharge) by reviewing permit applications and renewals, and investigating complaints against existing permits
- Requiring removal of roof rainleader and other clear-water connections from the sanitary sewer system to eliminate Combined Sewer Overflows (CSOs). For more information on the Rainleader Disconnect Program, see the Minneapolis CSO Solution .
The Chapter 52 Ordinance regulates everyone who disturbs topsoil and is designed to insure that soil does not leave an excavation site or enter any storm drain system, on either private property or the public right-of-way. All Minneapolis construction sites disturbing topsoil are subject to erosion and sediment control compliance. Sites disturbing more than five (5) cubic yards or five-hundred (500) square feet of topsoil, including utility excavations and any residential or commercial demolition projects, need an erosion control permit prior to the start of site work.
For demolition and construction sites greater than five-thousand (5,000) square feet, an approved erosion and sediment control plan is required before a permit will be issued for the site.
The Chapter 54 ordinance establishes requirements for land disturbing activities on sites greater than one acre, and specifies stormwater management standards according to the receiving water body. These standards include:
- The reduction of suspended solids to the Mississippi River
- Rate control for discharges to streams or areas prone to flooding
- The reduction in nutrients for discharges to lakes and wetlands
Stormwater management plans are required for all construction projects on sites greater than one acre in size. These plans are reviewed through the Minneapolis Public Works site plan review process. Following installation of stormwater devices, the permitting process requires registration, inspection and maintenance for each device registered by Minneapolis Regulatory Services. Sites less than one acre are encouraged to incorporate stormwater BMPs in their design as a means of satisfying other City codes, such as land use green space requirements.
Chapter 55 has restricted the sale and use of lawn fertilizers containing phosphorus since 2001. However, the use of phosphorus fertilizers is allowed for the first growing season when establishing new lawns (seed or turf) or if a soil test shows the need for phosphorus. The purpose of this ordinance is to reduce phosphorus pollution of our lakes, rivers and streams.
Lawn fertilizers contain nitrogen, phosphorus and potassium. The three numbers printed on the fertilizer bag, referred to as the "N-P-K" formulation, indicate the amount of nitrogen (N), phosphorus (P) and potassium (K) that is found in the fertilizer. Of these three nutrients, the amount of phosphorus needed by grass is much less than nitrogen or potassium. Additionally, soils in the Twin Cities area are typically higher in phosphorus, making lawn fertilizer applications of phosphorus unnecessary.
Prohibited Discharges to Sanitary Sewers
CSOs can occur when heavy rain or melting snow causes sanitary sewers to overflow into stormwater drainpipes. This allows sewage to mix with runoff from buildings, parking lots and streets and flow, untreated, into the Mississippi River. One way Minneapolis is attempting to eliminate CSOs is by mandating disconnection of any direct drainage of stormwater or clean non-stormwater discharges into the sanitary sewer system. Examples of this include:
- Area drains
- Sump pumps
- A/C coolant water
- HVAC water
Chapter 56. Prohibited Discharges to Sanitary Sewer System " Rainleader Ordinance," Minneapolis CSO Solution
Several Minneapolis departments work together by utilizing resources to protect residents, property and the environment from hazardous spills. Public Works, Fire Department, Regulatory Services and Emergency Communications all respond to both large and small spills.
Cleanup involves containment, source elimination and recovery. The release is first contained to prevent materials from spreading and making recovery more difficult. Storm drain catch basins may be blocked to prevent entrance to the storm drain system. After successful containment of the spill and elimination of further releases, recovery can begin.
Small spills may be recovered by applying sand to the site. After allowing time for spill to be absorbed, the sand is removed by a street sweeper. City of Minneapolis personnel perform a follow-up procedure to determine how the event occurred. This helps to determine any additional measures that might be taken to prevent spills in the future.
For large or extremely hazardous spills, the Fire Department's Hazardous Materials Response Team is mobilized instead of the local fire station. The State Public Safety Duty Officer may dispatch an emergency cleanup contractor.
Prohibited Discharges to Storm Drains
Complaints about unauthorized discharges (illegal dumping) of trash, oil, antifreeze or other contaminants into the storm drain system are received from many sources. This includes contractors, the public, as well as City staff. Maintenance crews regularly inspect stormwater structures, reporting any suspected evidence of illicit discharges to Minneapolis Regulatory Services. These reports are investigated to determine the appropriate action, which can include enforcement and possible fines or other penalties. Minneapolis residents can fill out a complaint form on the City's web page or call 311 or the Environment Services confidential tip line at (612) 673-5897.
Last updated Jan 30, 2012